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Drained ring-shear test data of wet silica powder-glass beads-PVC powder mixture “CM2” used for analogue modelling in the laboratory for experimental tectonics (LET) at RomaTre University, Rome, Italy

This dataset provides friction data from drained ring-shear tests on a wet (water saturated) silica powder-glass beads-PVC powder mixture (40:40:20 wt.%) “CM2”, used in analogue modelling of tectonic and erosion processes as a rock analogue for the earth’s upper crust (e.g. Conrad et al., 2023, Reitano et al., 2020, 2022. 2023). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of CM2 are µP = 0.66, µD = 0.58, and µR = 0.61, respectively. Cohesion of the material ranges between 60-230 Pa. The tested bulk material CM2 consists of a mixture of 40 wt. % silica powder, 40 wt.% glass beads and 20 wt.% PVC powder which has been saturated with water (Table 1). Specification of silica powder is “Ventilated Quartz VR16” (https://www.valligranulati.it/products-granules-quartz-marble-sands-premixed/sheet-m/ventilated-quartz) by the company Valli Granulati S.r.l. (Italy). Ventilated quartz is obtained by micronisation of quartz sands with a high content of SiO2 (around 96%), and used e.g. in paints and abrasives. It should be handled with care to omit generation of dust and a half mask (filter class FFA1P2 RD) should be worn because it can harm the human respiratory tract with the potential of causing silicosis. Glass beads used here have a size (diameter) of 700-110 µm and their individual properties are described in detail Pohlenz et al. (2020). The commercial name for the PVC powder is “PVC K.57 Inovyn 257RF” by the company TPV Compound (Italy). PVC powder is mainly used for cleaning industrial structures (as abrasives) or for the production of PVC tubing, plastic sheets etc. The composition of this PVC powder is the same of the common Polyvinyl chloride. According to the regulation CE n.1272/2008 (CLP), this type of PVC powder is classified as not dangerous for the supply, also thanks to its low value of density and round shape.

Rheology of viscous materials from the CNR-IGG Tectonic Modelling Laboratory at the University of Florence (Italy)

This dataset provides rheometric data of three viscous materials used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Earth Sciences Department of the University of Florence (Italy). The first material, PP45, is a mixture of a silicone (Polydimethylsiloxane or PDMS SGM36) and plasticine (Giotto Pongo). The PDMS is produced by Dow Corning and its characteristics are described by e.g. Rudolf et al. 2016a,b). Giotto Pongo is produced by FILA (Italy). Both components are mixed following a weight ratio of 100:45, and the final mixture has a density of 1520 kg m3. The second material, SCA705 is a mixture of Dow Corning 3179 putty, mixed with fine corundum sand and oleic acid with a weight ratio of 100:70:05 and a resulting density of 1660 kg m3. The final material, SCA7020 consists of the same components as SCA705, but with a slightly higher oleic acid content reflected in the weight ratio of 100:70:20. The mixture’s density is 1620 kg m3. The material samples have been analyzed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (20˚C). Rotational (controlled shear rate) tests with shear rates varying from 10-4 to 1 s-1 were performed. Additional temperature tests were run with shear rates between 10-2 to 10-1 s-1 for a temperature range between 15 and 30˚C. According to our rheometric analysis, the materials all exhibit shear thinning behavior, with high power law exponents (n-number) for strain rates below 10-2s-1, while power law exponents are lower above that threshold.For PP45, the respective n-numbers are 4.8 and 2.6, for SCA705 6.7 and 1.5, and for SCA7020 9.1 and 2.0. The temperature tests show decreasing viscosities with increasing temperatures with rates of -3.8, -1.4 and -1.9% per ˚K for PP45, SCA705 and SCA7020, respectively. An application of the materials tested can be found in Zwaan et al. (2020).

Rheometric measurements of salted type A gelatins

Gelatin is a versatile material commonly used in analogue modelling because of its complex rheology, which allows simulating a wide range of tectonic processes requiring either elastic (e.g., dyke intrusions models) and viscoelastic behavior (e.g., analog earthquakes models). Salt (NaCl) is generally added to gelatin to improve the scaling of the models by increasing the density of the material. The addition of salt results also in a weakening of the gelatin structure, which in turn can dramatically affect its rheological properties. Here, we provide raw data of rheometric measurements performed to test the rheological properties of type A (pig-skin) 2.5 wt% gelatin at T=10°C as a function of salt concentration and ageing time. Each sample was analyzed using dynamical oscillation tests (i.e., amplitude, frequency and time sweep tests) in shear strain controlled mode. All details about sample preparation procedure, measuring protocol, as well as results and data interpretation can be found in Brizzi et al. (2016).The data are provided as Excel files in *.xlsx format and comma-separated files in *.csv format. Each contains multiple measurements. In the Excel files, each measurement is presented as a table in different spreadsheets. In the comma-separated files, each measurement start with its own data series information, followed by the actual data. All files can be opened using MS Excel or equivalent software. An overview of tested salt concentrations and performed measurements can be found in the Explanation_Brizzi_et_al_2016.pdf file. A full list of the files included is given in List_of_files_Brizzi_et_al_2016.pdf.

Raw data (pictures, DEMs, .mat files) about analogue landscapes evolution

This dataset includes raw data used in the paper by Reitano et al. (2022), focused on the effect of imposed boundary conditions (regional slope and rainfall rate) on the morphological evolution of analogue landscapes; the paper also focuses on applicability of stream power laws on analogue models, defining if and how the parametrization used in natural landscapes works in analogue ones. The experiments have been carried out at Laboratory of Experimental Tectonics (LET), University “Roma Tre” (Rome). Detailed descriptions of the experimental apparatus and experimental procedures implemented can be found in the paper to which this dataset refers. Here we present: • Pictures recording the evolution of the models. • GIFs showing time-lapses of models. • Raw DEMs of the models, used for extracting data later discusses in the paper. • Raw channels data (.mat files).

Rheology of PDMS silicones used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (CUP)

This dataset provides rheometric data of three PDMS silicones used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (CUP). The material samples have been analyzed at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam (HelTec) using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (21˚C). Rotational (controlled shear rate) tests with shear rates varying from 10^4 to 1 s^-1 were performed. According to our rheometric analysis, the material is quasi-Newtonian (n~1) at strain rates below 10-2 s-1 and weakly shear rate thinning above. The viscosities of the three materials range between 8*10^4 to 3*10^5 Pa s.

Rheology of PDMS-corundum sand mixtures from the Tectonic Modelling Lab of the University of Bern (CH)

This dataset provides rheometric data of silicone (Polydimethylsiloxane, PDMS SGM36)-corundum sand mixtures used for analogue modelling in Zwaan et al. (2016, 2017), Zwaan and Schreurs (2017) and in the Tectonic Modelling Lab of the Institute of Geological Sciences at the University of Bern (CH). The PDMS is produced by Dow Corning and its characteristics have been described by e.g. Rudolf et al. (2016a,b). The corundum sand (Normalkorund Braun 95.5% F120 by Carlo Bernasconi AG: https://www.carloag.ch/shop/catalog/product/view/id/643), has a grainsize of 0.088-0.125 mm and a specific density of 3.96 g cm^-3. Further rheological characteristics are described by Panien et al. (2006). The density of the tested materials ranges between 1 (pure PDMS) and 1.6 g cm^-3 (increasing corundum sand content in mixture). The material samples have been analysed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature. Rotational (controlled shear rate) tests with shear rates varying from 10^-4 to 10^-1 s^-1 were performed.According to our rheometric analysis, the material is quasi Newtonian at strain rates below 10^-3*s^-1 and weakly shear rate thinning above. Viscosity and stress exponent increase systematically with density from ~4*10^4 to ~1*10^5 Pa*s and from 1.06 to 1.10, respectively. A first application of the materials tested can be found in Zwaan et al. (2016). Detailed information about the data, methodology and a list of files and formats is given in the "data description" and "list of files" that are included in the zip folder and also available via the DOI landing page.

Particle image velocimetry data from seismotectonic analog models focusing on the role of seamount subduction on megathrust seismicity

This dataset provides the surface velocity fields derived with MatPIV (open-source Matlab toolbox for Particle Image Velocimetry; Sveen 2004) of three seismotectonic analog models (e.g., Rosenau et al., 2017) performed to investigate the role of geometry and friction of a single subducting seamount on the seismogenic behavior of the megathrust. Model 1 has a seamount covered by sandpaper (i.e., high friction) that is placed at 1/2 of the trench-parallel length of the seismogenic zone. Model 3 has the same geometry of model 1, but the seamount is in direct contact with the gelatin (i.e., not covered by sandpaper, hence low friction). Model 5 has a low friction patch (i.e., no geometry) that is placed again at 1/2 of the trench-parallel length of the seismogenic zone. Together with the surface velocity fields, we also provide Matlab scripts for visualization. A more detailed description of the experimental setup, configuration of the models and materials can be found in Menichelli et al. (submitted), to which this dataset is supplementary. Our seismotectonic models represent a downscaled subduction zone (1 cm in the model corresponds to 6.4 km in nature; Rosenau et al., 2017). The experimental setup consists of a 60 x 34 cm2 Plexiglass box with a 10°-dipping aluminum basal plate that moves downward with a constant velocity of 0.01 cm/s, analog of the subducting plate. The overriding plate is represented by an elastic wedge of 2.5 wt% pigskin gelatin at T = 10 °C (Di Giuseppe et al., 2009). The seismogenic zone of the megathrust is simulated using a rectangular sandpaper patch (Corbi et al., 2013), with a downdip width of 16 cm and located 31 and 47 cm from the backstop. This corresponds to a 100-km-wide seismogenic zone extending over a depth interval between 15 and 34 km. The updip and down dip aseismic regions of the megathrust are simulated by plastic sheets that are fixed on the setup frame and not subject to subduction (Corbi et al., 2013). A 3D-printed PLA seamount is placed on the seismogenic zone (e.g., Van Rijsingen et al., 2019). The seamount has a height of 6.28 mm and a diagonal length of 94 mm, corresponding to 4 km and 60 km in nature, respectively. These dimensions scale well-known seamounts, such as the Joban Seamount chain in the Japan Trench or the Louisville seamount chain in the Tonga-Kermadec Trench. Experiments were monitored with a CCD camera that acquired a sequence of high-resolution top-view images (1600 x 1200 pixels2, 8 bit, 256 gray levels) at 7.5 fps for the entire duration of the experiment (i.e., ca. 24 minutes). Images are processed with Particle Image Velocimetry (PIV; Adam et al., 2005) using the open-source Matlab toolbox MatPIV (Sveen, 2004). MatPIV provides the velocity field between two consecutive frames, measured at the surface of the model. The velocity field was then used as input to identify analog seismic events using the open-source Matlab function findpeak. The threshold used was 0.1 cm/s. Once earthquakes were identified, we derived their source parameters such as seismic slip, magnitude, and recurrence time following Corbi et al. (2017) and van Rijsingen et al. (2019).

Supplement to "Analogue earthquakes and seismic cycles: Experimental modelling across timescales"

This data set contains various data derived from rock and rock analogue testing and analogue models which are presented in Rosenau et al. (2016) to which these data are supplement to..A first group of data contains animations of complementary analogue and numerical models of subduction zone earthquake cycles (A). A second group comprises analogue earthquake data and time series of surface deformation derived from scale models of subduction zone earthquake cycles (B). A third group consist of time series of stick-slip experiments using a ring shear tester (C). Finally, friction data both from rocks and rock analogue materials (D) as well as elasticity data from rock analogues are presented (E).See the Description of data and the List of files in the Data Download section for additional data description.

Ring-shear test data of corundum sand “NKF120” used for analogue modelling in the experimental tectonics laboratory at GFZ Potsdam

This dataset provides friction data from ring-shear tests on corundum sand “NKF120” used in analogue modelling of tectonic processes as a rock analogue for “strong” or “high density” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016) or as an additive to PDMS silicone oil to increase its density and non-linearity (Zwaan et al., 2018). According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.75, µD = 0.57, and µR = 0.62, respectively (Table 5). Cohesion of the material ranges between 100-150 Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities. The tested bulk material consists of corundum sand with grain size of 90-120 µm (Table 1). Corundum sand is produced as industrial abrasive materials and sold e.g. by the company Nico Bosse Strahlmittel Berlin. The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany.

Ring-shear test data of wallnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing))

This dataset provides friction data from ring-shear tests walnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the tested materials behave as a Mohr-Coulomb material characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.90, µD = 0.63, and µR = 0.68, respectively (Table 4). Cohesion of the material ranges between 0-40 Pa. The tested bulk material consists of walnut shells with grain size of 180-380 µm (Table 1) and is sold under the name "Walnut Shells" with the product number YR-98547 by the company Yiran Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

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